FrenchTF

Fixed! The secret is to remove the lock from the handle by releasing the catch which holds it into the handle (push the metal spring clip up, it will only go up as far as it needs to) before trying to remove the handle assembly .The lock comes out complete with the attached rod.
When replacing it’s easier to start to guide the lock back into the handle before pushing the handle assembly completely home. It's a right fiddle as space is really tight! 
No problem removing or replacing the two 8mm holding bolts - 1/4 drive socket with extension (actually further lengthened with a reducer and 3/8 extension). Fill the socket with grease to hold the bolt in place. 
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